Hydraulically-operated toothbrush

ABSTRACT

A HYDRAULICALLY-OPERATED TOOTHBRUSH HAS A PISTON ARRANGED TO BE RECIPROCATED BY PULSATING LIQUID. A SHAFT FOR CARRYING A TOOTHBRUSH HEAD IS MOUNTED FOR ROTATIONAL OSCILLATION. A COUPLING BETWEEN THE PISTON AND THE SHAFT OSCILLATES THE SHAFT AT A MULTIPLE OF THE RECIPROCATING FREQUENCY OF THE PISTON. ONE SPECIFIC COUPLING IS A PIN AND SLOT CONNECTION WHEREIN THE SLOT HAS SUCCESSIVE SECTIONS EXTENDING IN OPPOSITE ANGULAR DIRECTIONS. ANOTHER USES A PLUNGER TO OSCILLATE THE SHAFT, AND THE PISTON HAS AN ARM WHICH RECIPROCATES THE PLUNGER DIRECTLY DURING A PORTION OF ITS CYCLE, AND THROUGH ADDITIONAL MEANS SUCH AS A ROCKING LEVER DURING ANOTHER PORTION OF ITS CYCLE.

June 22, 1971 M. A. MORET ETAL HYDRAULICALLY-OPERATED TOOTHBRUSH 2 Sheets-Sheet 1 Filed Sept. 29, 1969 INVENTORS MICHEL A. MORET PlERREJ-JOUSSON ATTORNEYS June 22, 1971 M. A. MORET ETAL HYDRAULICALLY-OPERATED woo'msnusu Filed Sept. 29, 1969 2' Sheets-Sheot 2 mm I INVENTORS M EL A. MORET P REiJOUSSON B $44 6 M, #4. kfvam ATTORNEYS United States Patent 01 fice 3,585,669 HYDRAULICALLY-OPERATED TOOTHBRUSH Michel A. Moret and Pierre J. Jousson, Geneva, Switzerland, assignors to Institut de Recherche WOOG, Geneva, Switzerland Filed Sept. 29, 1969, Ser. No. 861,971 Claims priority, application Switzerland, Oct. 3, 1968, 14,801/ 68 Int. Cl. A46b 13/06 US. Cl. 1522 6 Claims ABSTRACT OF THE DISCLOSURE A hydraulically-operated toothbrush has a piston arranged to be reciprocated by pulsating liquid. A shaft for carrying a toothbrush head is mounted for rotational oscillation. A coupling between the piston and the shaft oscillates the shaft at a multiple of the reciprocating frequency of the piston. One specific coupling is a pin and slot connection wherein the slot has successive sections extending in opposite angular directions. Another uses a plunger to oscillate the shaft, and the piston has an arm which reciprocates the plunger directly during a portion of its cycle, and through additional means such as a rock ing lever during another portion of its cycle.

BACKGROUND OF THE INVENTION For a number of years power-operated toothbrushes, particularly electric toothbrushes, have been commerically available which allow cleaning the teeth and massaging the gums in accordance with oral hygiene requirements. More recently, pulsating water jet devices have been introduced which allow cleaning the interdental spaces as well as the sub-gingival margins. These devices have been recognized as being complementary to each other, and both should be used to obtain the best oral hygiene.

Hydraulically-operated toothbrushes are now available which, when connected to the pump unit of a water jet apparatus, provide a tooth'brushing action similar to that of an electric toothbrush. In such toothbrushes the frequency of oscillation or reciprocation of the brush head is the same as the frequency of the pulsating liquid from the pump unit.

Commonly, in water jet devices, the water pressure varies from a low pressure (say, about zero) to a maximum pressure at a frequency in the range of about 700 to 1250 pulsations per minute. Such frequencies are too low for efiicient brushing of the teeth. For a toothbrush, frequencies of at least about 2400 per minute are desirable.

SUMMARY OF THE INVENTION The present invention provides a hydraulically-operated toothbrush for actuation by pulsating liquid in which the frequency of oscillation of the toothbrush head is a mul tiple of the frequency of the pulsating liquid. This permits more efficient toothbrushing to be obtained, while at the same time allowing the use of pump units associated with conventional water jet apparatus.

In accordance with the invention, a reciprocating piston is provided which is driven by pulsating liquid from a suitable pump or other appropriate source, and coupling means are provided between the piston and the toothbrush shaft for rotationally oscillating the shaft at a fre- 3,585,669 Patented June 22, 1971 quency which is a multiple of the reciprocating frequency of the piston.

-In one specific embodiment of the invention described in detail hereinafter, the coupling means includes a pin and slot connection, and the slot has at least two successive sections extending in opposite angular directions so that the toothbrush shaft is rotated successively in opposite directions upon movement of the piston in one direction. This action takes place for both forward and reverse strokes of the piston, thereby giving the desired frequency multiplication.

In another specific embodiment described in detail hereinafter, =a plunger is coupled to the toothbrush shaft so that reciprocation of the plunger causes rotational oscil lation of the shaft. The reciprocating piston is provided with an arm which reciprocates the plunger directly during a portion of its cycle, and through additional means such as a rocking lever during another portion of its cycle, thereby producing two reciprocations of the plunger for each reciprocation of the piston.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall View of a hydraulically-operated toothbrush in accordance with the invention;

FIG. 2 is a longitudinal cross-section of the toothbrush in FIG. 1;

FIG. 3 is a detail of the pin and slot coupling of FIG. 2;

FIG. 4 is a longitudinal cross-section of another embodiment of the invention;

FIG. 5 is a detail showing the pin and slot connection of FIG. 4; and

FIGS. 6, 7 and 8 are cross-sections taken along the lines 66, 77 and 88 of FIG. 4.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS Referring to FIG. 1, the toothbrush includes a casing forming a handle, generally designated as 10, and a toothbrush head 11 removably attached to shaft 12 in any desired manner, such as by a pin and slot connection. Pulsating liquid from a suitable source such as the pump unit of a pulsating water jet device is supplied to the toothbrush through tube 13.

Referring to FIG. 2, within the casing 10 is a piston chamber 14 in which piston 15 is mounted for reciprocation. An inlet fitting 16 is provided at one end of the pis ton chamber and is arranged for convenient connection to supply tube 13. Suitable sealing means such as an O-ring 17 is provided at the other end of the piston chamber. A compression spring 18 resiliently biases the piston toward the inlet 16. Consequently, as the liquid pressure increases in chamber 14, the piston 15 is driven toward the left, and as the pressure decreases the spring 18 urges the piston toward the right, thereby reciprocating the piston at the frequency of the pulsations in the liquid supply to inlet 16.

The piston 15 has a rod element 19 attached thereto or integral therewith. A transverse pin 21 is affixed in the end of the rod and rides in slot 22 of a tube element 23 encircling the rod. Shaft 12 is aflixed in the end of tube element 23.

Referring to FIG. 3, slot 22 has two successive sections 22' and 22." which extend partially around the tube element 23 in opposite peripheral directions. The axial extent of the slot is at least equal to the axial extent of travel of rod 19 and pin 21. Consequently, as rod 19 moves in one direction, say to the left, the pin 21 first engages the wall of slot section 22' to rotate tube 23 in one direction, and then engages the wall of slot section 22 to rotate tube 23 in the opposite direction. The reverse takes place as rod 19 returns to its initial position. Accordingly, each reciprocation of the piston to which rod 19 is attached causes two rotational oscillations of tube 23, and consequently two oscillations of shaft 12 which carries the toothbrush head 11.

If desired, the slot 22 could have three or more sections successively extending in opposite directions so as to increase the multiplying factor between reciprocation of rod 19 and rotational oscillation of tube 23. Also, the functioning of the rod and tube element could be interchanged. That is, the tube element could be arranged to be reciprocated by piston 15 and the rod element could be attached to or form a part of shaft 12.

Referring now to FIG. 4, a piston arrangement is shown similar to that of FIG. 2 and the components are desig nated by the same numbers. A piston arm 31 is attached to the inner end of piston 15 and moves therewith. A slot 32 is provided in the piston arm and receives one arm of a rocking lever 33- pivoted in the casing at 34.

A plunger 35 having an actuating head 36 is mounted for reciprocation in the casing and is resiliently biased to ward the right by compression spring 37. The movement of plunger head 36 toward the right is limited by the face 38' of a cross bar 38 of the casing. A sliding pin 39 is located between plunger head 36 and the upper arm of rocking lever 33. A slot 41 allows free movement of the upper arm.

A transverse pin 42 is mounted at the end of plunger 35 and rides in a slot 43 in tube element 44. Shaft 12 is attached to tube element 42 in a manner similar to that of FIG. 2. As seen in FIG. 5, slot 43 extends partially around tube element 44 in only one peripheral direction. so that each reciprocation of plunger 35 causes a single oscillation of tube 44 and the attached shaft 12.

Describing the manner in which the mechanism of FIG. 4 functions, in the position shown the piston 15 is at the extreme right corresponding to a zero or low liquid pressure in inlet 16. The forward end of slot 32 is in engagement with the rocking lever 33 and the lever is in its extreme counterclockwise position. The upper arm of the lever is in engagement with pin 39 which in turn is in engagement with head 36 and the latter is at its extreme forward position. As the liquid pressure increases -in the piston chamber, piston 15 starts its forward stroke.

As the front end 31 of the piston arm moves forward, rocking lever 33 rotates clockwise by virtue of the force of compression spring 37 acting on plunger head 36 and pin 39. Plunger head 36 moves toward face 38'. As the front end 31' of piston arm reaches the plane of face 38', the plunger head 36 is substantially there. Upon further forward movement of the piston arm, the front end 31 thereof bears against plunger head 36 and forces it forward against the compression of spring 37. Upon completion of the forward stroke of the piston arm, the plunger head 36 will be in the position shown. However, inasmuch as the lower arm of rocking lever 33 will then be at the rear of slot 32, no force will be transmitted through the rocking lever and pin 39 to the plunger head.

On the return stroke of piston arm 31, as the front end 31 thereof moves back toward the plane of 38, the plunger head 36 will move toward the right until it reaches plane 38'. Also, pin 39 will move rearward and rocking lever 33 will be rotated clockwise. At substantially the time the plunger head reaches plane 38, the front end of slot 32 will engage the lower arm of rocking lever 33. As end 31 continues its return stroke past the plane of 38', the rocking lever 33 will be rotated counterclockwise and, through pin 39, will force the plunger head 36 forward until, at the end of the return stroke, it is in the position shown. Accordingly one reciprocation of piston 15 will result in two reciprocations of plunger head 36, and two ratational oscillations of shaft 12.

As will be noted, the plane of face 38' is midway between the forward and rear positions of the face of the front end 31 of the piston arm. Hence when end 31' is forward of plane 38' it directly engages plunger head 36 to cause reciprocation thereof. When end 31 is rearward of plane 38', an additional reciprocation is produced by rocking lever 33.

If desired, the slot arrangement shown in FIG. 3 could be employed in the embodiment of FIG. 4 so as to provide a further multiplying factor.

We claim:

1. A hydraulically-operated toothbrush for actuation by pulsating liquid which comprises (a) a casing forming a handle,

(b) an inlet in said casing for receiving said pulsating liquid,

(c) a piston chamber in said casing and a piston mounted for reciprocation therein,

((1) said inlet being connected to one end of said piston chamber and said piston being resiliently biased toward said one end whereby pulsating liquid produces reciprocation of said piston,

(e) a shaft at one end of said casing for carrying a toothbrush head and mounted for rotational oscillation,

(f) and coupling means between said piston and said shaft for rotationally oscillating said shaft at a frequency which is a multiple of the reciprocating frequency of said piston.

2. A toothbrush according to claim 1 in which said coupling means includes a pin and slot connection, said slot having at least two successive sections extending in opposite angular directions to rotate said shaft in successively opposite directions upon movement of said piston in one direction.

3. A toothbrush according to claim 1 in which said coupling means includes a rod element encircled by a tube element, one of said elements being connected for reciprocation by said piston and the other being connected for rotationallyoscillating said shaft, said tube element having a slot therein and said rod element having a transverse pin riding in said slot, said slot having an axial extent at least equal to the axial extent of travel of said one element and having at least two successive sections extending partially around the tube element in opposite peripheral directions.

4. A toothbrush according to claim 1 in which said coupling means includes (a) a plunger mounted for reciprocation in said casing and having an actuating head,

(b) a coupling between said plunger and said shaft for converting reciprocation of the plunger to rotational oscillation of the shaft,

(c) a piston arm attached to said piston and movable thereby between forward and rear positions,

((1) said plunger being movable between a forward position of said actuating head and a position thereof midway between the forward and rear positions of said piston arm and being resiliently biased toward the midway position,

(e) said piston arm engaging said plunger head at said midway position on the forward stroke thereof to move said plunger forwardly,

(f) and means responsive to movement of said piston arm from midway to rear positions thereof for moving said plunger from midway to forward positions thereof.

5. A toothbrush according to claim 4 in which the lastmentioned means includes a rocking lever pivoted in said 5 6 casing and having a pair of arms for coupling said pis- References Cited ton arm and plunger head during movement of the pis- UNITED STATES PATENTS ton arm from midway to rear positions thereof to move the plunger from midway to forward positions thereof. 3,484,885 12/1969 Deines al 15*22(R) 6. A toothbrush according to claim 5 in which said 5 FOREIGN PATENTS piston arm has a slot thereln for receiving one arm of 471,560 6/1969 Switzerland 15 22(R) said rocking lever, and including a pin positioned between the other arm of the rocking lever and said plunger head, the forward end of said slot engaging said one arm EDWARD ROBERTS Primary Examiner and said other arm engaging said pin during said move- 10 U S C1 X R ment of the piston arm from midway torear positions thereof to drive said plunger forwardly. 

